Refrigerator door latch



G. E. CURTISS, JR

REFRIGERATOR DOOR LATCH March 27, 1951 Filed May 25, 1948 2 Sheds-Sheetl ma; z.

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March 27, 1951 G. E. cUR-rlss, JR 2,546,333

A REFRIGERATOR DOOR LATCH Filed May 25, 1948 '2 Sheets-Sheet 2 F/cf. 5.

INVENTOR.

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Patented Mar. 27, 1951 UNITED STATES PATENT OFFICE REFRIGERATOR DOCRLATCH Application May 25, 1948, Serial N o. 28,987

This invention relates to latches of the type commonly used onrefrigerator doors.

More particularly, the invention relates to an improved latch of thegeneral type disclosed in my Patent No. 2,445,709, issued July 20, 1948,that is, a latch mechanism in which a progressively increasing latchingforce is exerted by the bolt as it approaches itsfully latched position,with the maximum available force being applied vat the time when thebolt member is fully the door is still open. When in the latterposition, andthe door is swung to closed position, one of the particularadvantages of the mechanism, is that the bolt is first urged into aretracted position from which it then moves into latching engagementwith said keeper. Thus, the bolt will move into latching engagement withthe keeper i whether the latch is in retracted or in advanced position,when the door is swung from open to closed position.

Inthe aforesaid latching mechanism it has been found necessary, when,they uncooked bolt isv moved toward latching engagement with the keeper,to overcome a, restraining force exerted by certain parts of themechanism; This force*- was overcome by applying a greater force to thedoor when closing it. In general, it, was highly desirable to solve thisproblem in such a way as to reduce, insofar as possible, the forcerequired to close the door under the abnormal condition above-noted and,in seeking such a solution, the present invention was conceived.

The invention has, therefore, as its primary object, theprovision of animproved latch mechanism of the` aforesaid' type.

More particularly, it is an object of the invention to provide a. latchmechanism characterized by itsV relative ease ofI operation and itsprompt actuationto fully latched position, regardless of` the positionof the, boltl when the. door is swung closed',

, These and other objects of the invention, hereV 4 Claims. (Cl.292-332) inafter appearing, will be more readily understood by referenceto the several views of the accompanying drawings, in which:

Figure 1 is a perspective View of a refrigerator embodying the presentinvention;

Figure 2 is a sectional view, on an enlarged scala, taken along theplane indicated by line 2 2, of Figure l, the latch mechanism beingshown in its fully latched position; l

Figure 3 is a view similar to Figure 2, but on a smaller scale, andshowing the mechanism in its normal unlatched and retracted condition,that is, with the bolt cocked, the door being shown in a position justprior to reaching its fully closed and latched condition;

Figure 4 is a view essentially similar to Figure 3, but illustrating thebolt in its uncooked position; and

Figure 5- is a sectional view on an enlarged scale, taken along the planindicated by line 5-5 of Figure 1, the latch mechanism being shown infully latched position.

Referring now to the drawings and more particularly to Figures 1 and 2,the numeral I0 designates a refrigerator comprising a cabinet II havinga door I2. As seen in Figures 2 and 5 the door comprises an inner panelI3 and an outer panel I4 joined about their peripheries at I5 (Figure 5)as by screws Il, which serve also to fasten the customary resilientsealing gasket I3 to the door, at that juncture. Gasket I8 is adapted toimpinge against the door jamb I9 of the cabinet and thereby provide anairtight seal between the door andA cabinet, when the door is closed.Mounted adjustably on the door jamb (Figure 2.) is a keeper which isprovided with a strike having a cam face 23, the purpose of which willbe explained hereinafter.

As more clearly shown in Figure 5 of the drawings, the latch includes asupport or housing 24 having a bottom wall 25 and a pair of parallelside walls 26V and 2l. The inner end of sidev Wall 26 is provided with aflange 28 through the agency of which the housing is secured to juno--ture I5 of the. inner and outer door panels, as`

secured by screws 29 to theperipheral flangel 30 of a support. member 3|welded, or otherwise suitablyV attached, to the outer door panel I4.Wthreference. to Figure 2, it is seen that a portion ofwallZSeXtendsupwardlybeyond flange:

30 of member`3l. This extension is provided with inwardly turned earportions 36 in which the ends of a pivot pin 31 are fixed. Pin 31extends through a slot 38 in an elongated latch bolt 39, which latter isadapted for movement about said pin into and out of latching engagementwith keeper 20 as hereinafter described.

Latch bolt 39 comprises a depending arm portion 40 which terminates atits lower end in a pair of spaced finger portions 4l and 42. Finger 42provides the keeper-engaging portion of the latch bolt, engagement beingfacilitated by a. pair of rollers 43, one being provided on each side ofits tip (see Figure `l Finger 4l is the trigger for moving the bolt fromits retracted position, shown in Figure 3, into extended Apositionengaging the keeper, as is more fully described hereinafter. The forceutilized to move the bolt into extended position is provided by a strongspring 44 positioned on arm 40, with one end impinging against shoulders45 of the link and its other end adapted to react against pin 31.

Movement of the bolt between extended and retracted positions, whenmoving in its normal mode of operation, is guided by a pair of links 46.Each of the links is pivotally mounted at one end on a pin 4, the endsof the latter being secured in side walls 26 and 21 of the housing,while the portion intermediate the ends of the pin passes between thefingers 4l and 42 of the bolt.

A particular feature of the invention, as more fully describedhereinafter, resides in the manner in which the other or free ends ofthe links engage the latch member to guide it in its normal latchingmovements, yet still permit free relative movement between said linksand member during abnormal latching movement. This engagement takesplace through a pin 48 which connects the free ends of the links and hasits intermediate portion engaged in a slot 49 formed in the portion ofthe bolt which bridges the space between ngers 4l and 42.

Still with reference to Figures 2 and 5, it is seen that the left-handend of pin 48 is provided with a roller 5l) positioned in the path ofmovement of an inwardly extending linger 5! of handle 52. The handle ispivotally mounted on a channelshaped member 54 welded or otherwisesecured, as indicated at 55, to bottom wall 25 of housing 24. The handleis normally biased toward its rest position, as shown in Figure 2, by aspring 56.

The operation of the latch is as follows:

As viewed in Figure 2, roller 43 is in latching position behind thestrike 22 of keeper 20. When it is desired to open the door the handle52 isl grasped and rotated in a counterclockwise direction about itspivot This movement urges the contacting surface Elia of handleextension 5l against roller 55 on pin 48, thus rotating the links in aclockwise direction about their pivot 41.

Rotation of these links, as described, moves latching member 39, againstthe pressure of spring 44, in a direction determined by the arcuatemovement of pin 48 about pin 41-as guided by engagement of pin 48 inslot -and to an extent withdrawing roller 43 from behind keeper 28, asseen in Figure 3, thereby permitting the door'to be swung open. Thismovement of latching member 39 continues until an extension 58 of oneside edge of slot 49 contacts pin 41, at which position, as indicated inFigure 3, pin 48 has moved to or preferably slightly past a position ofdead center with respect to pin 41 and the line of thrust of spring 44against pin 31. As illustrated in Figure 3 this dead center position isreached when the straight line between pins 31 and 48 corresponds to astraight line 51 intersecting the axis of pins 31 and 41. Release ofhandle 52 by the operator permits spring 56 to return the handle to itsnormal position as illustrated in Figure 2, while the latch remains inits retracted or cocked p0- sition.

To close and latch the door the latter is merely swung toward closedposition until trigger iinger 4I strikes the forward edge 22a of strike22 (Fig. 3) which causes the latching member to move to the left,shifting pin 48 back past the aforesaid dead center position, so thatthe thrust of spring 44 may operate to urge the mechanism toward latchedposition. At the instant pin 48 passes the line of dead center (51), itis urged by the pressure of the spring 44 to move in a counter-clockwisedirection toward the position illustrated in Fig. 2. This movementcauses the latching member 39 to move downwardly, and to the leftl asviewed in Figure 2, guided by links 46 and pin 31, bringing roller 43into contact with the keeper prior to completion of the link movement.Continued movement of the link draws the door forcibly into its fullyclosed position.

It is to be understood that, as the latching member approaches the fullylatched position, the lateral component of movement of said member, thatis, the component introduced by the strut-like action of links 46,becomes progressively smaller. Since, in a lever system of the kind hereinvolved, the product of the input force and the distance through whichthe force is acting is always equal to the product of the output forceand the distance through which the latter is acting, it will be evidentthat the aforesaid diminution of lateral movement is accompanied by acorresponding progressive increase in the lateral, or draw-in, force.

To a small degree, this increase in force is oiset by a progressivedecrease in the thrust of spring 44, but this is a minor factor.

Movement of the latching member in its downward or counter-clockwisedirection is terminated when the upper end of slot 38 contacts pin 31,as indicated at 31a. in Fig. 2, in which position pins 41 and 48 are inline with respect to the forces exerted against roller 43 so thatrebound forces against the roller are exerted in a straight line againstpin 41 and are thereby restrained.

Normal operation of the latch mechanism is as described above. However,when the mechanism is in the position illustrated in Fig. 3 and the dooris opened to an extent permitting access to the refrigerator foodstorage compartment, it may readily be seen that the roller end of thebolt projects outwardly of the door structure in a position exposed toinadvertent actuation by forces great enough to move pin 48 over thedead center position, as described above. Such inadvertent actuationpermits spring 44 to move the bolt to its latched position, while thedoor is still open.

In accordance with the foregoing statements of object and advantage, andas set forth in detail in what follows, the apparatus of the inventionis such that the door may be moved to fully latched position even if thebolt or latching member be uncooked when the door is swung closed, theinvention being particularly charactei-ized in that latching of thedoor, under such conditions, may be accomplished with considerably lessclosing force than was required with related mechanisms availableheretofore. This feature may best be understood with reference to Figure4.

When the door` is swung toward closed position-following inadvertentuncocking of the latch mechanism-roller 43 makes contact with cam face23 of the strike 20, rolls upwardly along said face and thus forces thelatch bolt 39 upwardly against the pressure of spring 44. This upwardmovement of the bolt or latching member takes place in a substantiallystraight line path determined both by pin 31 and slot 38, and by contactof the left hand edge 39a of bolt 39 against a guide member 26a fixed toside wall 26 of housing 24. The upward movement is of extent sufcient topermit the spring to move the roller 43 behind and into latchingengagement with the keeper, as the door continues its closing movement.It is to be noted that the strike face 23 is provided with a slopedportion 23a, in order to facilitate entry of the roller 43 into latchingposition behind said strike.

Under the abnormal mode of operation just described, the upward movementof bolt or member 39 is independent of and relative to links 46 and saidlinks are therefore not operative, as the roller 43 moves behind thekeeper, to provide the lateral, or draw-in force, described above.Hence, under such condition of operation, the force applied to the doorto effect closure thereof must be suicient both to raise the bolt 39against the pressure of spring 44 and to provide compression of the doorgasket. Accordingly it is of major importance that the total force whichmust be exerted against the door be kept as small as possible; In theapparatus of the presentinvention, substantially all of the forceexerted by the roller 43 against the inclined face 23 of the strike 2 isavailable to eiect the necessary raising of the latch bolt.

To this end, and in contradistinction to related mechanisms heretoforeavailable, the bolt is free to move with respect to the links 46, and itis therefore not necessary to overcome the restraining force which ispresent when the links 46 are pivotally secured to the latch bolt.Further, in the mechanism disclosed and claimed herein, the path ofupward movement of the latch bolt is in general alignment with thedirection of thrust reaction from the strike surface, thereby makingsuch reaction fully effective in raising the latch bolt.

, In the apparatus of the present invention, and as will now be evident,the latch bolt retracts through an unrestricted, substantiallystraightline path aligned with the direction of thrust reaction from thestrike surface and, therefore, retraction of the latch bolt is effectedonly against the force of spring 44, and such friction as exists in themechanism. The spring, when thus loaded, then operates to move the boltinto latching engagement with the keeper, in the manner described.

From the foregoing, it will be understood that the invention hereindisclosed and claimed provides apparatus which not only realizes thepositive action and secure draw-in required for proper latching of largeand heavy doors presently in commercial use but, further, is of such anature as to effect an important reduction in the force which must beapplied to the door to effect closure thereof when the latch bolt hasbeen inadvertently tripped and moved to uncocked position.

I claim:

1. In a door latch, the combination with support structure of anelongated latch member adapted for interlocking engagement at one endwith a keeper, means mounting the latch member for simultaneousoscillatory and longitudinal movement with respect to said structure,and means to control the oscillatory and longitudinal movements of saidlatch member so as to cause said latch member to move between aretracted position with respect to the keeper and an extended positionin which said latch member is in interlocking engagement with thekeeper, said control means comprising a spring exerting force tending toadvance the latch member into the said extended position, and meansguiding the movement of said latch member, said guide means comprisingan element having a portionadapted to react against said supportstructure, and another portionspaced from the rst mentionedportion-normally engaging said latch member in a manner to effectarcuate movement of the latch member from said retracted position tosaid extended position With progressively amplied force under theinfluence of said spring, the engagement between said element and saidlatch member further being such as to permit substantially straight linemovement of said latch member independently of said element, saidstraight line movement being from extended position out of latchingengagement with said keeper to extended position in latching engagementwith said keeper, and said guide means further including xed structureguiding said latch member in said straight line movement.

2. A door latch according to claim 1 wherein said guide elementcomprises a lever having one end thereof pivotally mounted for movementabout an axis on said structure, and its other end releasably engagingsaid latch member adjacent its keeper-engaging end.

3. A door latch in accordance with claim 2 wherein the releasableengagement of said lever with said latch member is effected through apin on said lever and a slot in the keeper-engaging end of said latchmember, said pin normally passing through said slot.

4. A latch in accordance With claim 3 Wherein the latch member, theguide means, and the mounting means are so related with respect to eachother that when the latch member is in retracted position, the point ofengagement of said lever with said latch member will lie to one side ofand closely adjacent to a straight line drawn between said axis and saidmounting means, and when in extended position the point will lie at theother side of and relatively remote to said line, and wherein said latchadditionally includes .stop means for stabilizing the member in saidpositions.

GEORGE E. CURTISS, JR.

REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES PATENTS Number Name Date 2,444,180 Anderson June 29, 19482,445,709 Curtiss July 20, 1948

